1. Field of the Invention
The present invention relates generally to inhalation devices. More particularly, the invention concerns a tee type nebulizer device for medicinal use that delivers an aerosol mist of properly sized particles of medicament to the patient at a very rapid rate.
2. Discussion of the Prior Art
Delivery of medication to a patient's lungs by means of jet nebulization has been an accepted procedure in the medical community for many years. Predominantly the device used has been a simple 3-way medical tee with one end interfaced to the patient, the other end open to room air, and the nebulizer component attached to an intermediate third port. Millions of these devices are produced and used annually.
Published data (Respiratory Care, Vol. 38, No. 38, Aug. 93; and Advance for Respiratory Care Practitioners Aug. 9, 1993) indicate that the most limiting factor in the use of aerosolized medication is the inefficient mist production by currently available commercial nebulizer systems. Research has shown that most state-of-the-art commercial units deliver less than 10% of the original dose of medication to the patient's respiratory tract. (Respiratory Care, Vol. 38, #8, August 1993; and AARC Times, June 1993.)
Jet nebulization is a process whereby a flow of gas (typically air or oxygen) through a very small orifice creates a partial vacuum in the fluid passageways of the device. This reduction in pressure is sufficient to create a Venturi effect, pulling liquid from a reservoir to mix into the gas stream. This liquid is subsequently changed within the device into aerosol particles.
Physical constraints in the design of jet nebulizers for medical use are such that the conversion rate of Liquid-to-aerosol is limited to a maximum of approximately 0.35 ml per minute of operation. This is a determining factor that determines the lengthy time (usually in excess of ten minutes) required for delivery of a clinically effective treatment when using any typical present day tee type nebulizer device. Not only is this wasteful, but because of the excessive time required for delivery of a clinically effective treatment, this type device is not user friendly. It is this problem that the present invention seeks to solve by improving the nebulizer design to include special baffling within the tee adapter of the device.